This invention relates generally to connector assemblies, and, more particularly, to a cable connector assembly which provides signal flow integrity between a mobile object such as a projectile or test vehicle and a stationary object such as a data processing facility during lift-off of the projectile. Additionally, the connector assembly permits reliable cable separation to take place at a predetermined point in the projectile trajectory.
There are many occasions when it is highly desirable to provide signal flow integrity between a movable and a stationary object. Generally such occasions arise during the lift-off of a projectile or test vehicle when information must be effectively relayed to a data processing facility. There are currently various systems or methods available for retrieving the test data is to be relayed between the projectile (mobile object) and the data collection or processing facility (stationary object). It is essential in each of these systems or methods to reliably provide communication between the projectile or mobile test vehicle and the stationary data processing facility. These prior techniques and systems have advantages and disadvantages which are directly dictated by one or more of the following factors:
1. the travel distance between the start of the projectile or test vehicle movement and the completion of the test and data acquisition period;
2. the amount of serviceable hardware to be salvaged at the conclusion of the test;
3. the volume of the data to be communicated between the projectile and the stationary data processing facility;
4. the structural integrity of the system and the safety of adjacent personnel;
5. the various stress/load dynamics subjected to the system;
6. the critical event timing requirements; and
7. the project budgeting and scheduling parameters.
Such prior methods and systems for data retrieval can be classified into two basic concepts. The first concept being data acquisition which requires electronic storage devices to be mounted in the projectile or mobile vehicle and the second being data acquisition techniques which involve the direct cabling between the projectile or the mobile test vehicle and a stationary electronic storage device located at the stationary processing facility.
A typical device which exemplifies the first type of method or system of data acquisition relies upon the use of a radio transmitter to relay test data to a stationary receiver located at the data processing facility during the test. Another such technique uses a data storage device which relies on an ejection/parachute mechanism to retrieve the test data after the test has been concluded.
Disadvantages inherent in the above two systems are, for example, the loss of extensive and/or expensive electronic components in the first case as well as problems arising from RF interference. The ejection mechanism and parachute in the second case must both function flawlessly or all the test data may be lost. Both methods or systems are not only expensive and highly vulnerable to various types of failure, but each has a limited capacity in the volume of data they may handle. These systems are therefore used primarily in tests that span great distances and require fewer channels of communication.
The second type of data acquisition techniques or systems involve the use of direct cabling between the projectile and the stationary data processing facility. These type of data retrieval systems overcome much of the problems associated with the first type of techniques described above since the volume of data to be communicated is unrestricted by virtue of the design of the system, require much lower budget impact, and greatly reduces the likelihood of electrical interference. The only drawback of such systems is their limitation to a reasonable travel distance of the mobile projectile between the start of the test and the completion of the test and data acquisition.
In general, however, the second type of data acquisition techniques or systems are preferable for projectile or test vehicle data acquisition. The following analysis of such systems provides information which must be taken into consideration when designing the cable connector of such data acquisition systems. One such cable connector provides release of the cable at the point of the mobile projectile or component. The advantage of such a release includes high salvageability of hardware and low load factors on the projectile. The disadvantages, however, include a high possibility of damage to surrounding objects, high launch dynamic forces at the separation of the connector and a cable arresting system is required.
A more reasonable cable connecting technique would involve release of the cable at the stationary component. The advantages of such a system are that there is little chance of damage to surrounding objects, no launch forces at the connector up to the point of separation, no cable arresting system is required and the overall range and safety factor is substantially increased. The disadvantage would be that there is less salvageable hardware and a slight increase in stationary facility load factors.
Currently there are three methods of release at the stationary component. These are (1) to blow the components apart; (2) to spring or push the components apart; or (3) to pull them apart as the cable becomes taut. The disadvantages in blowing or springing the connector apart is the requirement for explosive devices, compressed gases or springs which are contingent upon an event timing system to accomplish cable separation at a predetermined time. There are several factors, therefore, which make these methods vulnerable to failure and create range safety hazzards.
The pull-apart method represents the cleanest and most advantageous method of cable separation since there are fewer movable and/or stationary objects to entangle the data umbilical cord, potential damage to range structures is substantially reduced, no event timing or pyrotechnic devices are required, the procurement cost and lead time is reduced through in-house fabrication and the overall range safety factor is substantially improved. In view of the above factors, it is clearly evident that a pull-apart separation system or connector assembly would produce an ideal method of cable separation after the acquisition of test data from a projectile at liftoff.
Heretofore, prior attempts at such pull-apart separation systems or connector assemblies left much to be desired in the integrity of the cable connections, the insurance of separation at a proper time, and the salvageability of the greatest amount of hardware. As a result, such pull-apart techniques have generally not been used with past data acquisition procedures.